US20200000664A1 - Lockable wheels and subject support lifts including a lockable wheel - Google Patents

Abstract

A subject support lift includes a mast portion, a base portion, and a lockable wheel assembly coupled to the base portion. The lockable wheel assembly includes an axle member, a lockable wheel coupled to the axle member, and a pivot member pivotally coupled to the lockable wheel and defining an axis extending in a vertical direction, where the lockable wheel is rotatable about the axis defined by the pivot member. A locking member is coupled to one of the pivot member or the lockable wheel, the locking member being repositionable between a locked position, in which the locking member engages the other of the pivot member or the lockable wheel, and an unlocked position, in which the locking member is spaced apart from the other of the pivot member or the lockable wheel.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims the benefit of U.S. Provisional Patent Application No. 62/692,035, entitled “Lockable Wheels and Subject Support Lifts Including a Lockable Wheel” and filed on Jun. 29, 2018, the entirety of which is incorporated by reference herein.
BACKGROUNDField
• The present specification generally relates to subject support lifts including a lockable wheel and lockable wheels for use with subject support lifts.
Technical Background
• Mobile lifts may be used in hospitals, other health care facilities, and home care settings to move a subject from one location to another or to assist in moving a subject from one location to another. Conventional mobile lifts utilize various accessories, such as a sling or other attachments to secure a subject to the mobile lift. An actuator of the mobile lift may lift the subject in a vertical direction so that the subject may be transported from one location to another. In one example, a caregiver may operate the mobile lift to raise the subject off a bed, reposition the subject by moving the mobile lift to a desired location, and then lower the subject at the destination.
• When lifting a subject with a mobile lift, it is desirable to position the mobile lift directly over a center of mass of the subject. For example, when the center of mass of the subject is not positioned directly below the mobile lift, the subject may swing in a lateral and/or longitudinal direction when lifted, rather than moving only upward in the vertical direction. To address this issue, some conventional mobile lifts include pivoting wheels or casters that allow the mobile lift to move freely in the lateral and/or longitudinal direction. By moving in the lateral and/or longitudinal direction, the mobile lift may be repositioned over the center of mass of the subject as the subject is lifted. However, the pivoting wheels may make transporting the subject in the mobile lift difficult. For example, the pivoting wheels may provide minimal or no resistance to movement of the mobile lift in the lateral or longitudinal direction, making it difficult for a caregiver to push the mobile lift in a straight line, to navigate the mobile lift around an obstacle, or to otherwise move the mobile lift as desired.
• Accordingly, a need exists for devices to assist in navigating subject support lift along a desired path.
SUMMARY
• In one embodiment, a subject support lift includes a mast portion, a base portion, and a lockable wheel assembly coupled to the base portion, the lockable wheel assembly including an axle member, a lockable wheel coupled to the axle member and rotatable about an axle axis extending through the axle member, a pivot member pivotally coupled to the lockable wheel and defining an axis extending in a vertical direction that is transverse to the axle axis, where the lockable wheel is rotatable about the axis defined by the pivot member, a locking member coupled to one of the pivot member or the lockable wheel, the locking member being repositionable between a locked position, in which the locking member engages the other of the pivot member or the lockable wheel, and an unlocked position, in which the locking member is spaced apart from the other of the pivot member or the lockable wheel, a cable coupled to the locking member, and a handle coupled to the cable, where the handle selectively moves the locking member between the locked position and the unlocked position.
• In another embodiment, a subject support lift including a mast portion extending upward in a vertical direction, and a base portion positioned at a bottom end of the mast portion, the base portion including a lockable leg extending between a front end and a rear end, a lockable wheel assembly coupled to the lockable leg, the lockable wheel assembly including a pivot member coupled to the lockable leg, a lockable wheel pivotally coupled to the lockable leg at the pivot member, and a locking member repositionable between a locked position and an unlocked position, where the lockable wheel is rotatable with respect to the lockable leg about an axis extending through the pivot member in the vertical direction with the locking member in the unlocked position, and the lockable wheel is fixed with respect to the lockable leg about the axis extending through the pivot member with the locking member in the locked position.
• In yet another embodiment, a method for supporting a subject with a subject support lift includes moving the subject support lift toward the subject, the subject support lift including a mast portion and a base portion, the base portion including a lockable leg and a lockable wheel pivotally coupled to the lockable leg, moving the lockable leg outward from a subject support lift centerline, connecting the subject to the subject support lift, lifting the subject with the subject support lift in a vertical direction, locking the lockable wheel such that the lockable wheel is fixed with respect to the lockable leg about an axis extending in the vertical direction, and moving the subject connected to the subject support lift in a direction transverse to the vertical direction.
• Additional features of person lifting devices including lockable wheels described herein will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings.
• It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 schematically depicts a front perspective view of a subject support lift according to one or more embodiments shown and described herein;
• FIG. 2 schematically depicts a top view of the subject support lift ofFIG. 1, according to one or more embodiments shown and described herein;
• FIG. 3A schematically depicts a cross-section of a lockable wheel assembly of the subject support lift alongsection3A-3A ofFIG. 2, according to one or more embodiments shown and described herein;
• FIG. 3B schematically depicts a cross-section of the lockable wheel assembly ofFIG. 3A alongsection3B-3B ofFIG. 3A, according to one or more embodiments shown and described herein;
• FIG. 4 schematically depicts a cross-section of another lockable wheel assembly of the subject support lift along section4-4 ofFIG. 2, according to one or more embodiments shown and described herein;
• FIG. 5A schematically depicts a side view of another lockable wheel assembly of the subject support lift ofFIG. 2, according to one or more embodiments shown and described herein;
• FIG. 5B schematically depicts a rear perspective view of the lockable wheel assembly ofFIG. 5A, according to one or more embodiments shown and described herein;
• FIG. 6 schematically depicts a top view of another lockable wheel assembly of the subject support lift along section6-6 ofFIG. 1, according to one or more embodiments shown and described herein;
• FIG. 7A schematically depicts a top view of the lockable wheel assembly ofFIG. 6 rotating about an axis, according to one or more embodiments shown and described herein;
• FIG. 7B schematically depicts a top view of the lockable wheel assembly ofFIG. 6 continuing to rotate about the axis, according to one or more embodiments shown and described herein; and
• FIG. 7C schematically depicts a top view of the lockable wheel assembly ofFIG. 6 moving oriented in a lateral direction, according to one or more embodiments shown and described herein.
DETAILED DESCRIPTION
• Reference will now be made in detail to embodiments of lockable wheel assemblies and subject support lifts including lockable wheel assemblies, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. In embodiments, a subject support lift includes a mast portion extending upward in a vertical direction and a base portion positioned at a bottom end of the mast portion. The base portion includes a lockable leg extending between a front end and a rear end and a lockable wheel assembly including a pivot member coupled to the leg. The lockable wheel assembly includes a locking member and a lockable wheel pivotally coupled to the lockable leg at the pivot member, where locking member is repositionable between an unlocked position, in which the lockable wheel is rotatable with respect to the lockable leg about an axis extending through the pivot member in the vertical direction, and a locked position, in which the lockable wheel is fixed with respect to the lockable leg at the pivot member. Because locking member is selectively repositionable between a locked position and an unlocked position, the lockable wheel may be rotatable when lifting a subject, so that the subject support lift may freely move to position the subject support lift over the center of mass of the subject. The wheel may also be fixed with respect to the leg of the subject support lift in the locked position to resist movement of the lift in a lateral direction when moving the subject from one location to another. This and other embodiments of lockable wheels and subject support lifts including lockable wheels are described below with reference to the appended drawings.
• As used herein, the term “longitudinal direction” refers to the forward-rearward direction of the components of the subject support lift (i.e., in the +/−Y-direction as depicted). The term “lateral direction” refers to the cross-wise direction of the components of the subject support lift (i.e., in the +/−X-direction as depicted), and is transverse to the longitudinal direction. The term “vertical direction” refers to the upward-downward direction of the components of the subject support lift (i.e., in the +/−Z-direction as depicted).
• Referring initially toFIGS. 1 and 2, a front perspective view and a top view of asubject support lift100 are schematically depicted, respectively. Thesubject support lift100 generally includes amast portion102 extending upward in the vertical direction from abase portion101. Themast portion102 may include avertical member104 that generally extends upward in the vertical direction, and ahorizontal member106 that is pivotally coupled to and extends forward from thevertical member104 in the longitudinal direction. Thesubject support lift100 further includes asling bar108 that is selectively coupled to thehorizontal member106. Thesling bar108 may be utilized to selectively couple a subject support device (e.g., a sling, a vest, or the like) to thesubject support lift100.
• In embodiments, thesubject support lift100 includes amotor103 coupled to themast portion102 that moves thehorizontal member106 with respect to thevertical member104. In particular, in the embodiment depicted inFIGS. 1 and 2, themotor103 is positioned on thevertical member104 and engaged with thehorizontal member106. As noted above, thehorizontal member106 may be pivotally coupled to thevertical member104, and themotor103 may move thehorizontal member106 about the pivot, thereby moving thehorizontal member106 in the vertical direction. By movinghorizontal member106 in the vertical direction, themotor103 moves thesling bar108 selectively coupled to thehorizontal member106 in the vertical direction. Themotor103 may include any suitable actuation device to move thehorizontal member106 with respect to thevertical member104, such as a direct current (DC) electric motor, an alternating current (AC) motor, a pneumatically driven motor, a hydraulically driven motor, or the like. While the embodiment depicted inFIGS. 1 and 2 includes themotor103 coupled to thevertical member104 and engaged with thehorizontal member106, themotor103 may be positioned at any suitable location of thesubject support lift100 to move thehorizontal member106 with respect to thevertical member104. For example, themotor103 may be coupled to thehorizontal member106 or thebase portion101 to move thehorizontal member106, and accordingly thesling bar108, in the vertical direction. Furthermore, while the embodiment depicted inFIGS. 1 and 2 depicts amast portion102 including avertical member104 pivotally coupled to ahorizontal member106, it should be understood that themast portion102 may include any suitable construction to facilitate the selective movement of thesling bar108 in the vertical direction. For example, in some embodiments, thevertical member104 may include a telescoping design such that thevertical member104 may be selectively extended and retracted in the vertical direction, and themotor103 may move thevertical member104 up and down in the vertical direction to move thesling bar108 in the vertical direction.
• Thebase portion101 of thesubject support lift100 is positioned at a bottom end of themast portion102 and generally includes abase member110 extending in the lateral direction, and alockable leg120 and apivotable leg160 that are each pivotally coupled to thebase member110. Thebase member110 generally extends across a subjectsupport lift centerline10 that bisects thesubject support lift100 in the longitudinal direction.
• In the embodiment depicted inFIGS. 1 and 2, thelockable leg120 and thepivotable leg160 are pivotally coupled to thebase member110 atrespective pivot couplings112. Thelockable leg120 extends between arear end124 and afront end122 that is positioned opposite therear end124 in the longitudinal direction. Similarly, thepivotable leg160 extends between arear end164 and afront end162 that is positioned opposite therear end164 in the longitudinal direction. In embodiments, thelockable leg120 and thepivotable leg160 are repositionable between an extended position and a retracted position. In particular, thelockable leg120 is pivotable about apivot coupling axis114 of thepivot coupling112 that couples thelockable leg120 to thebase member110. Thelockable leg120 is repositionable between an extended position and a retracted position, where thefront end122 of thelockable leg120 is positioned closer to the subjectsupport lift centerline10 in the retracted position. Similarly, thepivotable leg160 is pivotable about apivot coupling axis114 of thepivot coupling112 that couples thepivotable leg160 to thebase member110. Thepivotable leg160 is repositionable between an extended position and a retracted position, wherein thefront end162 is poisoned closer to the subjectsupport lift centerline10 in the retracted position. In embodiments, thelockable leg120 and thepivotable leg160 may be coupled to amotor105 that selectively repositions thelockable leg120 and thepivotable leg160 between the extended position and the retracted position. In some embodiments, themotor105 may simultaneously move both thelockable leg120 and thepivotable leg160 between the extended and the retracted positions. In other embodiments, themotor105 may selectively move one or the other of thelockable leg120 and thepivotable leg160 between the extended and the retracted positions. By repositioning thelockable leg120 and/or thepivotable leg160 between an extended position and a retracted position, a distance d between thefront end122 of thelockable leg120 and thefront end162 of thepivotable leg160 may be increased or decreased. By increasing the distance d between thefront ends122,162 of thepivotable leg160 and thelockable leg120, thepivotable leg160 and thelockable leg120 may straddle an object supporting a subject such that thesling bar108 may be positioned over the subject. For example, a subject may be sitting on an object, such as chair, a toilet, or the like, and thepivotable leg160 and thelockable leg120 may be positioned on opposite sides to straddle the object such that thesling bar108 may be positioned over the subject.
• Thepivotable leg160 generally includes a pair ofpivotable wheels170 that are pivotally coupled to thefront end162 and therear end164 of thepivotable leg160. Thepivotable wheels170 are generally rotatable about pivotable wheel axes172 that extend in the vertical direction. Thelockable leg120 generally includes apivotable wheel170 pivotally coupled to therear end124 of thelockable leg120, and alockable wheel assembly130 coupled to thefront end122 of thelockable leg120. Thepivotable wheel170 pivotally coupled to therear end124 of thelockable leg120 is generally rotatable about thepivotable wheel axis172 extending in the vertical direction and thelockable wheel assembly130 is also generally rotatable about anaxis132 that extends in the vertical direction. Thelockable wheel assembly130 is selectively repositionable between a locked position, in which thelockable wheel assembly130 is fixed with respect to thelockable leg120 about theaxis132, and an unlocked position, in which at least a portion of thelockable wheel assembly130 is rotatable about theaxis132, as described in greater detail herein. While the embodiment depicted inFIGS. 1 and 2 includes thelockable wheel assembly130 coupled to thefront end122 of thelockable leg120, in other embodiments, thelockable wheel assembly130 may be coupled to therear end124 of thelockable leg120, and thelockable leg120 may include apivotable wheel170 coupled to thefront end122 of thelockable leg120.
• Referring toFIG. 3A, a cross-section view of thelockable wheel assembly130 alongsection3A-3A ofFIG. 2 is depicted. Thelockable wheel assembly130 is coupled to thelockable leg120, and generally includes apivot member140 coupled to thelockable leg120 and alockable wheel134 coupled to thepivot member140. In the embodiment depicted inFIG. 3A, thepivot member140 includes aconnection portion146 that is coupled to thelockable leg120 and that defines acavity148 extending upward into theconnection portion146. Thelockable wheel134 is pivotally coupled to thelockable leg120 through theconnection portion146, and thepivot member140 may include one or more bearings positioned between theconnection portion146 and thelockable wheel134 such that thelockable wheel134 is selectively rotatable about theaxis132. The bearings may include any suitable bearings to permit rotation of thelockable wheel134 with respect to thelockable leg120, such as ball bearings, roller bearings, magnetic bearings, or the like.
• Referring collectively toFIGS. 3A and 3B, the cross-section of thelockable wheel assembly130 alongsection3A-3A ofFIG. 2 and a cross-section of thelockable wheel assembly130 alongsection3B-3B ofFIG. 3A are depicted, respectively. Thelockable wheel134 is coupled to theconnection portion146 through anaxle member136 and thelockable wheel134 is rotatable with respect to theaxle member136. In particular, thelockable wheel134 is rotatable about anaxle axis131 that extends through theaxle member136 in the lateral direction as depicted, such that thelockable wheel134 may rotate along a surface, such as a floor.
• In embodiments, thelockable wheel assembly130 includes a lockingmember142 that is positioned at least partially within anaxle cavity137 defined by theaxle member136, such that the lockingmember142 is rotatable about theaxis132 with theaxle member136 and thelockable wheel134. The lockingmember142 may be bounded by theaxle cavity137 in the longitudinal and the lateral directions as depicted, such that movement of the lockingmember142 in the lateral and longitudinal direction is restricted by theaxle cavity137. In embodiments, the lockingmember142 is coupled to acable182 that extends through theconnection portion146 and that is movable in the vertical direction, to move the lockingmember142 in the vertical direction. Thecable182 may generally include any suitable structure to facilitate moving the lockingmember142 in the vertical direction, and may include a metal wire, a nylon rope, a composite, or the like.
• In some embodiments, the lockingmember142 is engaged with a biasingmember144 that biases the lockingmember142 in the vertical direction. The biasingmember144 may include any suitable construction to bias the lockingmember142 in the vertical direction, and may include a tension spring, a torsion spring, or a compression spring. In some embodiments, the biasingmember144 biases the lockingmember142 downward in the vertical direction. In other embodiments, the biasing member biases the locking member upward in the vertical direction.
• The lockingmember142 is repositionable between an unlocked position, as depicted inFIG. 3A and in which the lockingmember142 is spaced apart from thecavity148 of theconnection portion146, and a locked position, in which the lockingmember142 is positioned at least partially within thecavity148 of theconnection portion146. When at least a portion of the lockingmember142 is positioned within thecavity148 of theconnection portion146, movement of the lockingmember142 with respect to theconnection portion146 may be restricted. In particular, thecavity148 may bound the lockingmember142 in the longitudinal direction and the lateral direction, thereby restricting movement of the lockingmember142 with respect to theconnection portion146. As noted above, the lockingmember142 is bounded by theaxle cavity137 in the longitudinal and the lateral directions. Accordingly, when the lockingmember142 is positioned at least partially within thecavity148, the lockingmember142 is engaged with and bounded in the longitudinal and the lateral directions by both theconnection portion146 and theaxle member136. Because the lockingmember142 is bounded by thecavity148 of theconnection member146 and theaxle cavity137 of theaxle member136 in the longitudinal and the lateral directions, theaxle member136 is fixed with respect to theconnection member146 about theaxis132 when the lockingmember142 is positioned at least partially within thecavity148 of theconnection member146. By fixing theaxle member136 with respect to theconnection member146 about theaxis132, thelockable wheel134 may be fixed with respect to thelockable leg120 about theaxis132 through theaxle member136, the lockingmember142, and theconnection portion146. In the embodiment depicted inFIGS. 3A and 3B, the lockingmember142 is positionable within thecavity148 of theconnection portion146 when thelockable wheel134 is aligned with thelockable leg120, e.g., when theaxle axis131 extends in a direction orthogonal to thelockable leg120.
• Referring collectively toFIGS. 1 and 3A, in some embodiments, thecable182 is coupled to ahandle180. In the embodiment depicted inFIGS. 1 and 3A, thehandle180 is coupled to themast portion102 and is coupled to the lockingmember142 through thecable182. Thehandle180 is repositionable between an engaged position, in which thehandle180 moves the lockingmember142 into the locked position, and a disengaged position, in which thehandle180 moves the lockingmember142 into the unlocked position. As described above, the biasingmember144 may bias the lockingmember142 in the vertical direction. In some embodiments, the biasingmember144 biases the lockingmember142 into the cavity148 (i.e., into the locked position), and the lockingmember142 is moved into the unlocked position throughmovement cable182 in the vertical direction via moving the handle into the disengaged position. In other embodiments, the biasingmember144 may bias the locking member out of the cavity148 (i.e., into the unlocked position), and the lockingmember142 is moved into the locked position through movement of thecable182 in the vertical direction via moving thehandle180 into the engaged position.
• Referring again toFIG. 1, by fixing thelockable wheel134 with respect to thelockable leg120 about theaxis132, the lateral movement of thesubject support lift100 may be restricted. More particularly, because thelockable wheel134 is fixed with respect to thelockable leg120 about theaxis132 with the locking member142 (FIG. 3A) in the locked position, thelockable wheel134 may be rotatable about the axle axis131 (FIG. 3A), but may resist movement in the lateral direction as depicted. By resisting movement in the lateral direction, thelockable wheel134 may reduce the force required to navigate thesubject support lift100 along a straight line in the longitudinal direction, reducing the burden placed on a caregiver to move thesubject support lift100 as desired when transporting a subject with thesubject support lift100. Furthermore, by resisting movement in the lateral direction, thelockable wheel134 may provide a pivot point about which the rest of thesubject support lift100 may be rotated, which may assist a caregiver in navigating thesubject support lift100 as desired when transporting a subject with thesubject support lift100.
• However, when lifting a subject with thesubject support lift100, it may be desirable for thelockable wheel134 to be rotatable with respect to the lockable leg about theaxis132. In particular, as noted above, thesubject support lift100 includes thepivotable wheels170 at thefront end162 and therear end164 of thepivotable leg160, as well as at therear end124 of thelockable leg120, each of which are rotatable about pivotable wheel axes172 that extend in the vertical direction. Because thesubject support lift100 includespivotable wheels170 and thelockable wheel assembly130 that are each rotatable aboutaxes172,132 extending in the vertical direction, thesubject support lift100 may move freely in the lateral and the longitudinal directions through the rotation of thepivotable wheels170 and thelockable wheel assembly130. Free movement of thesubject support lift100 may be desirable when lifting a subject with themast portion102, such that thesubject support lift100 may be moved to align thesling bar108 over a center of mass of the subject.
• For example and referring toFIG. 2, thesling bar108 defines a sling bar center of mass109, and a subject to be moved with thesubject support lift100 may define a subject center ofmass12. When lifting the subject in the vertical direction through a sling, a vest, or the like coupled to thesling bar108, it is desirable for the sling bar center of mass109 to be positioned over the subject center ofmass12. In particular, once a subject is lifted off of a support surface (e.g., a bed, a chair, or the like), the subject center ofmass12 will move toward the sling bar center of mass109 under the force of gravity. In other words, the subject will “swing” toward the sling bar center of mass109, and may continue swinging until the subject center ofmass12 comes to rest underneath the sling bar center of mass109. To reduce “swinging” the subject, it is desirable to align the sling bar center of mass109 with the subject center ofmass12 before the subject is lifted off of the support surface.
• With thesubject support lift100 freely movable in the longitudinal and the lateral direction, as thesling bar108 moves upward in the vertical direction, thesubject support lift100 may be “pulled” toward the subject center ofmass12 until the sling bar center of mass109 is positioned over the subject center of mass109. Without being bound by theory, as thesling bar108 moves upward in the vertical direction, the sling bar108 (through a sling, a vest, or the like coupled to thesling bar108 and attached to the subject) applies a force to the subject, which is resisted by an equal and opposite force applied to thesling bar108 by the subject. The force applied to thesling bar108 by the subject acts to pull thesubject support lift100 toward the subject center ofmass12. With thesubject support lift100 freely movable in the longitudinal direction, thesubject support lift100 moves toward the subject center ofmass12 under the force applied to thesling bar108 by the subject (i.e., in aforward direction14 and in a sidewayslateral direction16 as depicted), until the sling bar center of mass109 is positioned over the subject center ofmass12. As thesling bar108 continues to move upward, the subject may then be lifted off of a support surface (e.g., a bed, a chair, or the like) with the sling bar center of mass109 positioned over the subject center ofmass12. In this way, a subject's “swinging” when being lifted by thesubject support lift100 may be minimized by utilizing asubject support lift100 includingpivotable wheels170 and alockable wheel assembly130 that are each rotatable aboutaxes172,132 extending in the vertical direction allowing thesubject support lift100 to move freely in the lateral and the longitudinal directions.
• Accordingly, by including a selectivelylockable wheel134, thesubject support lift100 may be freely movable in the lateral and the longitudinal directions when lifting a subject so as to reduce swinging the subject as described above, and lateral movement of thesubject support lift100 may be restricted when moving a subject in the longitudinal direction with thesubject support lift100.
• Referring toFIG. 4, a cross-section of anotherlockable wheel assembly130 is depicted along section4-4 ofFIG. 2. The embodiment depicted inFIG. 4 includes theconnection portion146 including thecavity148, thelockable wheel134, and theaxle member136 including theaxle cavity137, similar to the embodiment described above with respect toFIGS. 3A and 3B. However, in the embodiment depicted inFIG. 4, thelockable wheel assembly130 includes asolenoid184 that moves the lockingmember142 between the locked position and the unlocked position. Particularly, thesolenoid184 may be selectively charged with current to draw the lockingmember142 upward in the vertical direction. In the embodiment depicted inFIG. 4, thecable182 electrically couples thesolenoid184 to the handle180 (FIG. 1). In this embodiment, thecable182 may generally include a construction suitable for conducting electrical current, such as copper wiring or the like.
• Thelockable wheel assembly130 further includes the biasingmember144 that biases the lockingmember142 in the vertical direction. In the embodiment depicted inFIG. 4, the biasingmember144 may bias the lockingmember142 downward in the vertical direction (i.e., into the unlocked position), and thesolenoid184 may move the lockingmember142 into the locked position when charged with current. In other embodiments, the biasingmember144 may bias the lockingmember142 upward into the cavity148 (i.e., into the locked position), and thesolenoid184 may move the lockingmember142 into the unlocked position when charged with current.
• Referring toFIGS. 5A and 5B, a side view and a lower perspective view of anotherlockable wheel assembly130 is schematically depicted. Thelockable wheel assembly130 includes thelockable wheel134 and thepivot member140 coupled to thelockable leg120. In the embodiment depicted inFIGS. 5A and 5B, thelockable wheel assembly130 further includes adisc150 that extends at least partially around theaxis132 of thelockable wheel assembly130. In embodiments, thedisc150 is coupled to thelockable wheel134, such that thedisc150 rotates about theaxis132 of thepivot member140 with thelockable wheel134.
• Thelockable wheel assembly130 further includes the lockingmember142 that is selectively engageable with thedisc150. In particular, in the embodiment depicted inFIGS. 5A and 5B, the lockingmember142 is coupled to thelockable leg120 and is extendable in the longitudinal direction to selectively engage thedisc150. When extended, the lockingmember142 engages thedisc150, such that thedisc150, and accordingly thelockable wheel134, are fixed with respect to thelockable leg120 about theaxis132. When retracted, the lockingmember142 is spaced apart from thedisc150, such that thedisc150, and accordingly thelockable wheel134, are rotatable with respect to thelockable leg120 about theaxis132. In embodiments, the lockingmember142 may be coupled to the handle180 (FIG. 1) through a cable182 (FIG. 3A) and the lockingmember142 may be extended and retracted (i.e., moved between the locked position and the unlocked position) via movement of the handle180 (FIG. 1) between the engaged position and the disengaged position.
• Referring now toFIG. 6, a cross section of anotherlockable wheel assembly130 along section6-6 ofFIG. 1 is schematically depicted. In the embodiment depicted inFIG. 6, thepivot member140 defines thecavity148, and lockingmember142 of thelockable wheel assembly130 includes aturnable axle281 positioned within thecavity148. Theturnable axle281 is coupled to thelockable wheel134 and generally includes an elliptical shape having a turnable axlemajor axis280 and turnable axleminor axis282. Thecavity148 similarly includes an elliptical shape having a cavitymajor axis248 and a cavityminor axis250. In embodiments, a length of the turnable axlemajor axis280 is less than a length of the cavityminor axis250, such that theturnable axle281 is rotatable within thecavity148. Furthermore, theturnable axle281 is coupled to thelockable wheel134 such that theturnable axle281 rotates with thelockable wheel134 with respect to thecavity148 about theaxis132.
• Theturnable axle281 may move within thecavity148 in the longitudinal and/or the lateral directions. When the subject support lift100 (FIG. 1) is moving forward in the longitudinal direction (i.e., in the +y-direction as depicted), theturnable axle281 may be positioned in a front end of thecavity148 such that the turnable axlemajor axis280 and the cavitymajor axis248 are aligned and the turnable axleminor axis282 is positioned forward of the cavityminor axis250 in the longitudinal direction. With the turnable axlemajor axis280 and the cavitymajor axis248 aligned and with theturnable axle281 positioned in the front end of thecavity148, rotation of thelockable wheel134 about theaxis132 may be restricted. More particularly, with theturnable axle281 positioned within the front portion of thecavity148, theturnable axle281 may be bounded by the elliptical shape of thecavity148, restricting rotation of theturnable axle281, and accordingly thelockable wheel134, about theaxis132. In this manner, theturnable axle281 may be positioned in the locked position when the subject support lift100 (FIG. 1) is moving forward in the longitudinal direction.
• Referring collectively toFIGS. 7A-7C, theturnable axle281 is depicted progressively rotating about theaxis132 until thelockable wheel134 is oriented in the lateral direction. More particularly, as depicted inFIG. 7A, theturnable axle281 may be moved rearward within thecavity148 in the longitudinal direction (i.e., in the −y-direction as depicted). In embodiments, theturnable axle281 may be moved rearward within thecavity148 when the subject support lift100 (FIG. 1) ceases moving forward in the longitudinal direction (i.e., in the +y-direction as depicted), and/or by moving the subject support lift100 (FIG. 1) rearward in the longitudinal direction (i.e., in the −y-direction as depicted). As theturnable axle281 moves rearward within thecavity148, theturnable axle281 may no longer be bounded by the elliptical shape of thecavity148, allowing rotation of theturnable axle281, and accordingly thelockable wheel134, about theaxis132. As noted above, the length of the turnable axlemajor axis280 may be less than the length of the cavityminor axis250, such that theturnable axle281 may be fully rotatable about theaxis132 when theturnable axle281 is positioned at the center of thecavity148. In this way, theturnable axle281 may be repositioned between the locked position and the unlocked position by moving theturnable axle281 forward and rearward in the longitudinal direction within thecavity148. Because theturnable axle281 is positioned in the locked position when the subject support lift100 (FIG. 1) is being moved forward in the longitudinal direction, similar to the embodiments described above, thelockable wheel assembly130 may assist in resisting lateral movement of the subject support lift100 (FIG. 1) when thesubject support lift100 is being moved forward in the longitudinal direction.
• Accordingly, it should now be understood that embodiments according to the present disclosure include subject support lifts including lockable wheel assemblies. The lockable wheel assemblies generally include a locking member and a lockable wheel pivotally coupled to a lockable leg of the subject support at the pivot member, where locking member is repositionable between an unlocked position, in which the lockable wheel is rotatable with respect to the lockable leg about an axis extending through the pivot member in the vertical direction, and a locked position, in which the lockable wheel is fixed with respect to the lockable leg at the pivot member. Because locking member is selectively repositionable between a locked position and an unlocked position, the lockable wheel may be rotatable when lifting a subject, so that the subject support lift may freely move to position the subject support lift over the center of mass of the subject. The wheel may also be fixed with respect to the leg of the subject support lift in the locked position to resist movement of the lift in a lateral direction when moving the subject from one location to another.
• It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.

Claims (20)

What is claimed:

1. A subject support lift comprising a mast portion, a base portion, and a lockable wheel assembly coupled to the base portion, the lockable wheel assembly comprising:

an axle member;

a lockable wheel coupled to the axle member and rotatable about an axle axis extending through the axle member;

a pivot member pivotally coupled to the lockable wheel and defining an axis extending in a vertical direction that is transverse to the axle axis, wherein the lockable wheel is rotatable about the axis defined by the pivot member;

a locking member coupled to one of the pivot member or the lockable wheel, the locking member being repositionable between a locked position, in which the locking member engages the other of the pivot member or the lockable wheel, and an unlocked position, in which the locking member is spaced apart from the other of the pivot member or the lockable wheel;

a cable coupled to the locking member; and

a handle coupled to the cable, wherein the handle selectively moves the locking member between the locked position and the unlocked position.

2. The subject support lift ofclaim 1, wherein the lockable wheel assembly further comprises a biasing member engaged with the locking member.

3. The subject support lift ofclaim 1, wherein the pivot member comprises a connection portion coupled to the lockable wheel, the connection portion defining a cavity, and wherein the locking member is positioned within the cavity in the locked position, and the locking member is spaced apart from the cavity when the locking member is in the unlocked position.

4. A subject support lift comprising:

a mast portion extending upward in a vertical direction; and

a base portion positioned at a bottom end of the mast portion, the base portion comprising:

a lockable leg extending between a front end and a rear end;

a lockable wheel assembly coupled to the lockable leg, the lockable wheel assembly comprising:

a pivot member coupled to the lockable leg;

a lockable wheel pivotally coupled to the lockable leg at the pivot member; and

a locking member repositionable between a locked position and an unlocked position, wherein the lockable wheel is rotatable with respect to the lockable leg about an axis extending through the pivot member in the vertical direction with the locking member in the unlocked position, and the lockable wheel is fixed with respect to the lockable leg about the axis extending through the pivot member with the locking member in the locked position.

5. The subject support lift ofclaim 4, wherein the lockable wheel is coupled to the front end of the lockable leg.

6. The subject support lift ofclaim 4, further comprising a handle coupled to the mast portion, wherein the locking member of the lockable wheel assembly is coupled to the handle.

7. The subject support lift ofclaim 6, further comprising a cable coupled to and extending between the handle and the locking member, wherein the handle is movable between an engaged position, in which the handle moves the locking member into the locked position through the cable, and a disengaged position, in which the locking member is in the unlocked position.

8. The subject support lift ofclaim 4, wherein the lockable wheel assembly further comprises a biasing member engaged with the locking member.

9. The subject support lift ofclaim 8, wherein the biasing member biases the locking member into the unlocked position.

10. The subject support lift ofclaim 8, wherein the biasing member biases the locking member into the locked position.

11. The subject support lift ofclaim 4, wherein the lockable wheel assembly further comprises a disc coupled to the lockable wheel and extending at least partially around the axis extending through the pivot member, and wherein the locking member engages the disc in the locked position and the locking member is spaced apart from the disc in the unlocked position.

12. The subject support lift ofclaim 4, wherein the pivot member comprises a connection portion coupled to the lockable leg, the connection portion defining a cavity, and wherein the locking member is positioned within the cavity in the locked position and the locking member is spaced apart from the cavity in the unlocked position.

13. The subject support lift ofclaim 12, wherein the lockable wheel assembly further comprises a solenoid that selectively moves the locking member between the locked position and the unlocked position.

14. The subject support lift ofclaim 4, wherein the pivot member defines a cavity comprising an elliptical shape having a cavity major axis and a cavity minor axis, and the locking member comprises a turnable axle positioned within the cavity and coupled to the lockable wheel, wherein the turnable axle comprises an elliptical shape having a turnable axle major axis and a turnable axle minor axis.

15. The subject support lift ofclaim 14, wherein the turnable axle major axis is aligned with the cavity major axis in the locked position and the turnable axle minor axis is positioned forward of the cavity minor axis in a longitudinal direction that is transverse to the vertical direction.

16. The subject support lift ofclaim 4, wherein the base portion further comprises a pivotable leg positioned opposite the lockable leg and extending between a front end and a rear end positioned opposite the front end in a longitudinal direction that is transverse to the vertical direction, wherein the pivotable leg is repositionable between a retracted position and an extended position, and wherein the front end of the pivotable leg is positioned closer to a subject support lift centerline in the retracted position than the extended position; and

a pivotable wheel coupled to the pivotable leg, the pivotable wheel being rotatable with respect to the pivotable leg about a pivotable wheel axis extending in the vertical direction.

17. A method for supporting a subject with a subject support lift, the method comprising:

moving the subject support lift toward the subject, the subject support lift comprising a mast portion and a base portion, the base portion comprising a lockable leg and a lockable wheel pivotally coupled to the lockable leg;

moving the lockable leg outward from a subject support lift centerline;

connecting the subject to the subject support lift;

lifting the subject with the subject support lift in a vertical direction;

locking the lockable wheel such that the lockable wheel is fixed with respect to the lockable leg about an axis extending in the vertical direction; and

moving the subject connected to the subject support lift in a direction transverse to the vertical direction.

18. The method ofclaim 17, further comprising, prior to lifting the subject with the subject support lift, unlocking the lockable wheel such that the lockable wheel is rotatable about the axis.

19. The method ofclaim 17, wherein locking the lockable wheel comprises aligning a turnable axle major axis of a turnable axle coupled to the lockable wheel and comprising an elliptical shape, with a cavity major axis of a cavity defined by a connection portion coupled to the lockable leg and comprising an elliptical shape.

20. The method ofclaim 17, wherein lifting the subject further comprises moving the subject support lift in at least one of a longitudinal direction and a lateral direction that are transverse to the vertical direction to align a center of mass of a sling bar coupled to the mast portion of the subject support lift with a center of mass of the subject.

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